Five days after taking Alpo Petfoods Inc. off the market, an official of the parent company visited Alpo headquarters and ordered top management to move out. Ian A. Martin, who heads American operations for Grand Metropolitan PLC of Great Britain, Alpo's parent, broke the news Tuesday to Frank Krum, Alpo president and chief executive officer, and Willard H. Cressman, senior vice president of finance. Alpo's 1,500 employees were informed later that day that Krum, 56, was being replaced by Rob Hawthorne, 45, previously president and chief executive officer of Pillsbury Canada, also part of Grand Metropolitan. Industry analysts Wednesday attributed the move to the expensive promotional campaign to introduce Alpo's new cat food. Krum will serve as a special adviser to Martin on trade and industry relations. Cressman has elected not to stay with the company, a Grand Met spokeswoman said. Krum, Cressman and Hawthorne were unavailable for comment. The 54-year-old pet food company was put up for sale Feb. 8, when Grand Met Chairman Allen Sheppard decided it didn't fit into the conglomerate's plans to focus on its human foods business. Alpo spent $70 million in promotions and advertising for the introduction of its cat food this year, including the use of the cartoon character Garfield. Alpo, the sixth-largest pet-food maker in the United States, now holds 9 percent of the $1.3 billion canned cat food market and 5 percent of the $1.1 billion dry cat food market, analysts said. Alpo, which earned $45 million in 1989 on sales of about $400 million, expects cat food sales to top $100 million in 1990. Because of the rapid growth of its cat food sales, Alpo was pulled off the market May 24. Martin said Grand Met and potential buyers were ``not able to reach agreement as to the value of Alpo's recently launched cat food business.''